Mr Draper said once the fire had been put out they discovered paper pushed up around the motor and cab, leading them to believe the fire was suspicious.
"We immediately notified police and got hold of the driver and the owner of the truck."
The driver, Colin Bateman, said the fire had the potential to do "serious damage".
"It's got two 400-litre diesel tanks. If the truck had gone up and those had exploded it would have done damage to the neighbourhood.
"Every window in the pretty big radius would have been blown in."
He said he had been parking the truck in the same place for five or six months without incident and could not think of any reason for him or the company to be targeted.
"It's likely to be kids, they obviously didn't know anything about trucks based on the way they tried to light it."
He said balls of newspaper had been shoved up under the cab and around the motor but only some of them had been lit.
"I'd say they'd been disturbed when they were lighting the paper."
Mr Bateman, who is based in Hawke's Bay, was attempting to get the truck repaired yesterday afternoon.
"It's more just annoying stuff, I've got to get all the electronics checked over in Hastings and I need to use it tomorrow (Monday) night at 5pm so hopefully it's possible to get it fixed by then."